1. Field of the Invention
The present invention relates to a valve device using a planetary component for opening and closing a valve plate.
2. Description of Related Art
As an embedded valve device embedding valve plates between opposite valve seats, a sluice valve is known to the prior art (referring to FIG. 1 of Patent Reference 1). However, in order to open and close a valve, it is necessary to turn a handle 30. Hence, a relatively long time is required for the opening and the closing of the valve. In addition, the height of the valve is relatively large, and a relatively great thrust is required to open and to close the valve. Further, in order to ensure that the valve plate 31 is closed, it is necessary to perform an adjustment (processing), so as to assure the tight sealing of the seal faces of the valve plates 31 and the valve seats 32.
In view of the problems that the time for the opening and closing of the valve becomes longer and the height of the valve device becomes larger, a following method is considered, in which a planetary gear is used in constituting the valve plates to solve the problems (Patent Reference 2 and Patent Reference 3).
[Patent Reference 1] Japanese Patent Utility Model Publication No. JP 56-76773U, the current Gazette of the sluice valve
[Patent Reference 2] Japanese Patent Publication No. JP 61-59435B Gazette
[Patent Reference 3] Japanese Patent Publication No. JP 63-46309B Gazette
However, the valve plates are in sliding contact with the guide portions of the valve plates when the planetary gear is used in constituting the valve plate. Further, due to the tolerances or mutual friction of the teeth of the planetary gear, the sun gear, and the internal gear, the degree of freedom of the valve plate becomes limited. Therefore, the valve function of closing the valve plates and the valve seats, i.e. the closing capability, is inadequate.
In addition, the following aspects still require improvement. The seal faces of the valve seats are in sliding contact with the moving valve plates, such that the seal faces are damaged, inducing an adverse effect on the closing function of the valve.
In another aspect, when the planetary gear is used in constituting the valve plates, the following problem is still unsolved. That is, it is necessary to reduce the current operating force on the sluice valve; or in order to assure the closing function of the valve, it is necessary to perform the adjustment (processing).